1. Field of the Invention
The invention relates to a nitro compound, an amine compound, a polyimide, and a polyimide copolymer. More particularly, the invention relates to a new nitrophenyl compound containing a triphenylamide group, a new phenylamine compound fabricated with the nitrophenyl compound, a new dinitro compound fabricated with the phenylamine compound, a new diamine compound fabricated with the dinitro compound, a new polyimide and a new polyimide copolymer fabricated with the aforementioned diamine compound and at least one dianhydride compound.
2. Description of Related Art
Polyimide (PI) is currently one of the most important engineering plastics. With the features of superior thermal stability, resistance to chemical reagents, low dielectric constant, abrasion resistance, low thermal expansion coefficient and other properties, PI is a good candidate to be widely applied as electronic material in relevant electronic industries such as automobile industry, semiconductor industry, precision machinery industry, soft printed circuit board, liquid crystal display (LCD), and other electronics industries.
Although PI has superior heat-resistance and mechanical characteristics, the problem of unfavorable processability is usually present. Moreover, PI has high melting point or softening point and therefore can not be processed by heating and melting. Also, PI has low solubility, and thus can not be processed to form by dissolving with a solvent. Hence, most of aromatic PIs have difficulties in the formation processing.
Some patents disclosed that the rigidness of molecular chain is reduced by introducing soft fats, such as a straight alkyl group (—CH2—), into the structure, so as to enhance solubility of polymer. However, the heat-resistance of polymer is usually reduced at the same time.